限食对前列腺癌小鼠抑瘤作用的初步观察

Tumor suppression effect of dietary restriction in mice with prostate cancer

目的观察限食对皮下移植型前列腺癌小鼠的抑瘤作用,并比较不同限食方法的疗效差异。方法将60只C57BL/6雄性小鼠随机分成模型组、每日2 g组和隔日4 g组,每组20只。每日2 g组每日投放常规饲料2 g,隔日4 g组隔日投放常规饲料4 g,余组自由摄食。造模后22 d、25 d、28 d、31 d、34 d、37 d及40 d在小鼠体表测量瘤体的最长径和最短经,计算瘤体体积;同时记录各组小鼠的生存时间,计算生命延长率。另将80只C57BL/6雄性小鼠随机分成空白组、模型组、每日2 g组和隔日4 g组,每组20只。在造模前、造模后5 d、10 d、15 d、20 d、25 d及30 d测量小鼠体质量;造模后35 d摘眼球取血测量血清TNF-α浓度;并断颈椎处死小鼠,剥离瘤体测量瘤体质量,计算抑瘤率。结果模型组小鼠体质量随着瘤体的生长逐步上升,在第15 d开始快速生长,高于且持续高于空白组(P<0.05);而每日2 g组和隔日4 g组在造模后第15 d降至最低,之后开始平缓回升,造模后第30 d体质量仍低于正常组和模型组(P<0.05),但限食组间差异无统计学意义(P>0.05)。每日2 g组和隔日4 g组的瘤体体积在造模后第22 d小于且持续小于模型组(P<0.05),但限食组组间差异无统计学意义(P>0.05)。每日2 g组和隔日4 g组剥离的瘤体质量均小于模型组(P<0.05),但限食组组间差异无统计学意义。Kaplan Meier生存分析显示,模型组、每日2 g组和隔日4 g组生存率组间差异无统计学意义(P>0.05)。模型组、每日2 g组和隔日4 g组小鼠血清TNF-α浓度组间差异无统计学意义(P>0.05)。结论限食具有一定的抑瘤作用,间断性较大幅度限食和持续性低幅度的限食抑瘤作用无显著差异,限食抑瘤作用机制与TNF-α相关机体免疫功能途径无明显相关性。

Objective To observe the preliminary observation of dietary restriction in mice with prostate cancer and compare its effects in mice treated by different kinds of dietary restrictions. Methods Sixty C57 BL /6 male rats were randomized into treatment group,2 g group and 4 g group,with 20 mice in each group.Mice in 2 g group were treated by conventional dietary 2 g per day,and mice in 4 g group were treated by conventional dietary 4 g every other day. The other groups were fed normally. Measure the longest diameter and shortest diameter of tumor at the 22 th,25th,28 th,31th,34 th,37th,40 th day after the model establishment to calculate volume of tumor. The survival time and the life prolonging rate were recorded. Other 80 C57 BL /6 male mice were randomly divided into normal control,model group,2 g group and 4 g group,with 20 mice in each group. Measure the weight before the model establishment and the 5th,10 th,15th,20 th,25th,30 th day after the model establishment; measure the tumor weight and the serum TNF- α concentration on the 35 th day after the model establishment.Removed the weight of tumor after sacrificed to calculate its tumor inhibition rate. Results The model group weight gradually increased with the tumor grew,and larger than the normal control group since the 15 th after the model establishment with tumor rapid growth（P〈0.05）. The weight of the 2 g group and 4 g group were decreased and the lowest on the 15 th after the model establishment,then gradually increased with tumor grew,but still lower than the normal control group and the model group on the 30 th after the model establishment（P〈0.05）,and no significant difference between the two groups. The tumor volume of the 2 g group and 4 g group were smaller than that of the model group since the 22 nd after the model establishment（P〈0.05）,but no significant difference between the two groups. The tumor weight of the 2 g group and 4 g group were lower than that of the model group（P〈0.05）,but no significant difference between the two groups. There was no significant difference with the serum TNF-α concentration among the groups. Conclusion Dietary restriction has the restrain effect on tumor,and there was no significant difference between intermittent dietary restriction and continuously chronic dietary restriction. No relaventive relationship between dietary restriction and TNF-α.